My wife and I are flying AUS-LAS r/t next weekend, and I have been using itn to look at loads. Out of AUS, it looks great, nice empty? flight (i.e. 9-9-9-9-9-9-9) but on the return (on NWA metal through MEM) it had looked like the return was overbooked (i.e. 9-9-3-1-0-0-0-0-0-0-0)but lately it has increased capacity...7-5-2-0-0-0-0-0. We would really be interested in getting 'bumped', and I wa shoping this flight would be overbooked (an extra night in LAS) so I have 2 questions.

1) What is the likelihood this flight is overbooked
2) Do the airlines add capacity to a flight in an attempt to overbook...and if they overbook by a certain amount do they change the aircraft type..i.e. upgrading from an A320?

Any help would be appreciated...by the way, the numbers are not symbolic in #, just a representation of COACH class designators...Y etc...we are at the lowest (cheap ticket).

Also, I guess I have three questions. We are ticketed by CO (working towards CO silver) does that increase/decrease the chances of a bump?

Thanks, Mike